In 1988, Gregory S. Paul claimed to have found evidence of a hyperextensible second toe, but this was not verified and accepted by other scientists until the Thermopolis specimen was described. scientists have realized that it bears even more resemblance to its ancestors, the Maniraptora,  Older potential avialans have since been identified, including Anchiornis, Xiaotingia, and Aurornis. Most of these eleven fossils include impressions of feathers. (2018).. Most of the specimens of Archaeopteryx that have been discovered come from the Solnhofen limestone in Bavaria, southern Germany, which is a lagerstätte, a rare and remarkable geological formation known for its superbly detailed fossils laid down during the early Tithonian stage of the Jurassic period, approximately 150.8–148.5 million years ago.  Lowe (1935) and Thulborn (1984) questioned whether Archaeopteryx truly was the first bird. Over the years, ten more fossils of Archaeopteryx have surfaced. In 1960, Swinton accordingly proposed that the name Archaeopteryx lithographica be placed on the official genera list making the alternative names Griphosaurus and Griphornis invalid. The study also found that the avialans Jeholornis and Sapeornis grew relatively slowly, as did the dromaeosaurid Mahakala.
It reads “Feder von Archaeopteryx lithographica”, which is German for “Feather of Archaeopteryx lithographica”, and is the text written on the slab of rock that bears the feather.  Despite the presence of numerous avian features, Archaeopteryx had many non-avian theropod dinosaur characteristics.
Archaeopteryx skeletons are considerably less numerous in the deposits of Solnhofen than those of pterosaurs, of which seven genera have been found. is a matter still open for debate. , The first skeleton, known as the London Specimen (BMNH 37001), was unearthed in 1861 near Langenaltheim, Germany, and perhaps given to local physician Karl Häberlein in return for medical services. Feathers may have originally From Simple English Wikipedia, the free encyclopedia. It could reach up to 500 millimetres (20 in) in body length, with an estimated mass of 0.8 to 1 kilogram (1.8 to 2.2 lb).
 They also misinterpreted the fossils, claiming that the tail was forged as one large feather, when visibly this is not the case.  Their suggestions have not been taken seriously by palaeontologists, as their evidence was largely based on misunderstandings of geology, and they never discussed the other feather-bearing specimens, which have increased in number since then. , There is no indication of feathering on the upper neck and head. It was named from a single feather in 1861, the identity of which has been controversial. Videler, JJ (2005) Avian Flight. Paul also criticized the measurements of the rachises themselves, noting that the feathers in the Munich specimen are poorly preserved. , A patch of pennaceous feathers is found running along its back, which was quite similar to the contour feathers of the body plumage of modern birds in being symmetrical and firm, although not as stiff as the flight-related feathers. , In 2007, a review of all well-preserved specimens including the then-newly discovered Thermopolis specimen concluded that two distinct species of Archaeopteryx could be supported: A. lithographica (consisting of at least the London and Solnhofen specimens), and A. siemensii (consisting of at least the Berlin, Munich, and Thermopolis specimens). , Archaeopteryx continues to play an important part in scientific debates about the origin and evolution of birds. Archaeopteryx seemed to confirm Darwin's theories and has since become a key piece of evidence for the origin of birds, the transitional fossils debate, and confirmation of evolution. The authors of the follow-up study noted that uncertainties still exist, and that it may not be possible to state confidently whether or not Archaeopteryx is a member of Avialae or not, barring new and better specimens of relevant species. The lifestyle of Archaeopteryx is difficult to reconstruct and there are several theories regarding it. evolved for insulation and then been co-opted into flight. In March 2018, scientists reported that Archaeopteryx was likely capable of flight, but in a manner distinct and substantially different from that of modern birds. In the Berlin specimen, there are "trousers" of well-developed feathers on the legs; some of these feathers seem to have a basic contour feather structure, but are somewhat decomposed (they lack barbicels as in ratites). Archaeopteryx. -- Is This Bird A Fraud?, an excellent essay that not only reviews Specimens of Archaeopteryx were most notable for their well-developed flight feathers.  This study was criticized by Philip J. Currie and Luis Chiappe. The thumb did not yet bear a separately movable tuft of stiff feathers. , A twelfth specimen had been discovered by an amateur collector in 2010 at the Schamhaupten quarry, but the finding was only announced in February 2014. are debated. Archaeopteryx looked like a small carnivorous dinosaur with wings and feathers.